Posted
by
samzenpus
on Monday February 21, 2011 @06:11AM
from the what-time-is-now dept.

Anonymous Coward writes "In England it has been proposed that the clocks move forward by 2 hours this summer to give us more daylight time in the day, and hopefully in turn stimulate the economy. My question is what impact will this hold for computers that automatically adjust the time to British Summer Time? Could this cause another 'millennium Bug' fiasco?"

Y2K was a much different situation [wikipedia.org], one which had absolutely nothing to do with such concepts as "daylight savings," "summer time," and the like. Y2K was caused by silly computer abbreviation of dates, and while DST [wikipedia.org] can cause timekeeping bugs, it's unlikely to cause a worldwide meltdown.

I would also like to point out that these things are much more likely to break down the more frequently you change them..

Many people in the UK are accustomed to assuming that localtime always equals GMT. The side effect is many think that GMT = BST when it's in effect. I once worked for an airline and out of necessity, I got REALLY good at timezone math. I once asked for clarification whether a conference call in the middle of July was going to be 16:30 GMT or 16:30 BST and I could hear the blank stares on the line.

It's presumably only talking about changing Summer time. IIRC useful daylight in summer is usually from around 5AM to maybe 10:30PM, so this would change our daylight from 6-11:30. That would be pretty cool.

I think they're wanting BST to be GMT+2 (Ie, CEST) and Normal time to be GMT + 1 (Ie, CET)
we would, basically, be moving to Central European Time.

However, this can be vetoed by the Scottish Parliment. I hope it does, or else we'll be having dawn at 9am during winter.

I agree - this should never get off the drawing board. Basically it takes as an assumption that nobody does anything useful in the morning before work. Some of us happen to like the extra hours of daylight in the morning before work because it gives us a chance to go for a run, or work on our own projects or fit in a decent breakfast or whatever.

Most of us wake up more easily and naturally with the daylight than before sunrise, so Summer means extra time and energy for us. The UK government seems to think that's free productivity that they can tap into for the sake of its economy.

Those are not state capitals you see listed; they are merely "landmark" major cities within each time zone. State capitals are often mid-sized cities, usually chosen for geographic reasons, or even specifically to avoid putting the capital in any of the state's largest cities; as a Scot you probably wouldn't recognize half of them by name. The U.S. did the same thing when the federal capital was created, and when we get around to making the home countries of the UK into the 51st-54th states, we'll probabl

I would also like to point out that these things are much more likely to break down the more frequently you change them.

I think that sums it up best . ..

OTOH, if people changed these things more frequently, things in general would become less likely to break down, because everyone would become more accustomed to it. We would then be able to relegate those people who allow it to break down to the same caste we today relegate the "what do you mean someone can insert random SQL in my obviously numeric GET parameter?!" people. They would still exist, but nobody would really pay attention to their screams:)

It's no secret that France has long wanted the Meridian to pass through Paris, where other items that define weights and measure reside, so they can all be in one (*ahem* French *ahem*) place.
Once we don't use Greenwich Mean Time the next step will be for France to re-name Paris as "Greenwich",...

Heh. Apparently the French (and probably a lot of Brits, too) haven't heard that GMT hasn't been used for a quarter century now. The Greenwich Observatory got out of the time standard business back in 1986 (google it), when the official time standard was redefined in a way that wasn't dependent on any place or artifact, and renamed "UTC". Since then, "GMT" has been nothing more than a mispelling of "UTC", usually by someone who doesn't understand the difference.

Actually, if you visit the Greenwich Observatory, you'll find that they do have a nice museum exhibit of the history of their time standard, as well as a number of other good exhibits. It's well worth spending a day of your vacation there. Or visit their nice web site (www.nmm.ac.uk [nmm.ac.uk]).

I have yet to see one single study that finds economical benefits in using DST. Actually, in the programmers' world, we see a lot of systems costing more because of this : Because DST regulations change almost every year (and I am not talking about leap seconds) the only away to have an accurate local time on a device is to have either regular maintenance or to link the device on internet to receive updates (and add some work to ensure the security of this, which can cost a lot on critical systems). I wish politician computed this cost. They manages to make the simple task of telling the local time too hard for a computer to compute on its own. That is really an achievement on their part.

The Wikipedia page lists some studies, but I find this one most revealing:

A 2008 study examined billing data in Indiana before and after it adopted DST in 2006, and concluded that DST increased overall residential electricity consumption by 1% to 4%, due mostly to extra afternoon cooling and extra morning heating; the main increases came in the fall. The overall annual cost of DST to Indiana households was estimated to be $9 million, with an additional $1.7-5.5 million for social costs due to increased pollution.

There may be benefits to DST, but DST does not save energy, one of the original arguments for DST.

Keep in mind, the main purpose of DST is to get people up earlier in the morning so that they don't waste that daylight. People are used to getting to work/school by some set time, say 8 AM. If you told them that in the summer, they had to get to work/school by 7 AM, even though they could leave an hour earlier, most people would balk. But if you tell them that 7 AM is really 8 AM, they don't seem to have any problem, and they'll happily go along with it.

Now, maybe it's easier to just redefine the hours of the day this way than having different schedules for winter and summer months. Lots of people are easily confused by time, and changing your clocks is a one time event, then everything else is "normal." I do find it humorous that people like to keep this convenient fiction, though. If we never had DST and someone proposed it, I think most people would find it ridiculous. But since most people have done it all their life, it's just what we do in the spring and fall (and they think that places that don't do it are somehow backwards and wrong). Just a matter of perspective, I guess.

The rules for starting and ending U.S. daylight saving time and British Summer Time are both set by legislation and have changed several times [wikipedia.org]. Hard coding them into software is a serious mistake. The only safe way to deal with DST is to maintain a lookup table for the specific dates each year or a list of the years when the rules changed, and update these tables regularly. The more often the rules change, the more incentive people will have to adopt appropriate practice, rather than encrusting their softwa

I can predict a worse outcome for the economy than people simply not being at work early. We currently get 3 hours of overlap with the (east coast) americans in a work day – they don't really want to have meetings absolute first thing, and we don't really want to have one last thing... This would give us only 2 hours overlap and compound the cross-atlantic communication problem.

If it happened tomorrow? It would cause a few problems. If it happens in March? Probably enough time to fix it. If it happens in October or later, no problem. There's usually somewhere in the rest of the world changes their DST policies on a yearly basis -- I believe parts of the U.S. changed in the last year or two.

It's an OS patch which you wouldn't even notice, a new tzdata file or similar.

Why dont we just skipp falling back one autum instead of springing forward two hours in the spring. It would make more sense as it always makes me tired in the mornings when we change the clocke in the spring and two hours seams like a nightmare come Monday morning when the whols country has jetlag.

That's the plan for the winter, but they want the summer time to still be pushed further forward. So, we'll be in UTC+1 for the winter, UTC+2 for the summer, instead of UTC and UTC+1. This means more sunshine in the evening, when I'm awake, and less in the morning, when I'm asleep, so I'm in favour of it. We play ultimate frisbee from about 5:30 in the afternoon during the summer, but we have to stop as soon as the clocks change, because we've run out of daylight, even if it's not raining (improbable, bu

So, we'll be in UTC+1 for the winter, UTC+2 for the summer, instead of UTC and UTC+1.

Isn't there some fundamental irony here? I mean, UTC is based on GMT [wikipedia.org]. This proposal is intended to fundamentally shift the time zone away from the meridian that was originally defined... by the UK... that runs right through the UK.

The prime meridian is completely arbitrary, but out of the whole world, the UK was allowed to choose it and then base GMT/UTC from it. The more interesting implication is that this proposal is an effort to ensure your "noon" is no longer ever defined as the point when the sun i

Just, you know, some of us don't want to go to work in the dark. All the bloody time. I fail to see how moving to CET could possibly bring in extra billions to the economy. Dubious economics aside, however, what on Earth is wrong with living in a time zone that reflects your physical location on the globe? I mean, moving Grenwich off of Grenwich mean time permanently is enough of a misnomer to put me off the idea, but WHY would anyone want to mandate that we all get out of bed an hour earlier in the morning? I find the shift to/from BST bad enough as it is - if this became twice as large a shift, it'd be twice as bad, and if it were an "all year-round" change, most of Scotland would see no light til 11am in the winter. How that's a good idea I don't know... people seem to forget that the "extra" hour is just being stolen from the other end of the day!

That is indeed a possible reason for the change. Tinkering with time conversion algorithms were in the past also attributed to the economy stimulus it would give the IT sector. That being said, I've read some British press that they want to move to the CET, since that is their main trading zone. A switch which I think will not have the economic effect they might hope for. Countries trading with the UK know there is a time difference and make sure that they handle any issues within the time window. Switching

There's no need to tinker with time conversion algorithms. They're not introducing new time zones, they're just moving to the same time zone most of the rest of Europe uses. All that it needs is an update changing GB->GMT/BST to GB->CET/CEST. Any software that knows about time zones will already know about CET and CEST. The only programs that are likely to have a problem are ones that hard code the mapping from locales to time zones.

The main reason given for doing it is to make the journey to and from school/work safer by having more usable daylight. It was tried in the 70s and worked very well, but some farmers objected and somehow got their way.

There are two options on the table at the moment. We could go to GMT+1 with DST as well (so GMT+2 when DST is in effect) or we could just stick with GMT+1 all year. I would prefer the latter and it works well enough in much larger countries like Japan that span multiple time zones.

That is indeed a possible reason for the change. Tinkering with time conversion algorithms were in the past also attributed to the economy stimulus it would give the IT sector.

Wonderful. So can we count on the next proposal to be sending someone around to bust out everybody's windows, so that we get an economic stimulus in the window industry? And I think the car tire industry could use a stimulus, so what do you think we could do about that?

Not at all. One of the issues with this change is it is largely driven by the English outlook - while it's understandable in terms of population distribution, it means that regions which are further north and west suffer quite seriously in terms of daylight hours. For example, sunrise in N. Ireland is typically about 40 to 45 minutes later than London in winter. If they go through with the most extreme change being discussed (that is, moving to match CET year-round) parts of N. Ireland and Scotland won't se

Oh, suck it up. I live at 63N, and we're just now starting to get sunrise around the time we go to work. It's inconvenient, but not "very unpleasant", and if you don't like it just go live on a tropical island.

Quite a few people find it depressing leaving work several hours after the sun has gone down. Can't please everyone!

Right. In winter, I go to work before sunrise and leave after sunset, which is pretty depressing. Then again, in summer I go to sleep before sunset and wake up after sunrise, which is pretty nice.

(I live in Finland, little over 62 degrees North. In mid-winter there's about 4 hours between sunrise and sunset; in midsummer, 20 hours. Here, shifting the clocks for daylight savings never made any real sense, except in synchronizing schedules with other countries. Today, it makes little sense anywhere, and it'd

With the DST changes that Congress mandated a few years ago, I think most commercial and Open Source OS's could adapt to this change easily.Since we're no longer bound by Railroad timetables, especially in the UK, the concept of standard time and the time zones truly becomes much more localized. What I fear is one day cities will adopt their own time zones rather than regionally. Wouldn't that be fun? It would be like George Carlin's gag.

I think the bigger impact for some people will be being even further ahead of the US in terms of timezone. At the moment 5 hours is okay, I work with people in the Middle East, Europe, UK and the east coast, from the UK and this is manageable at the moment. I don't start work until about 9 and then work till about 7 or 8 if needed. This gives me a good amount of overlap with everyone. If this goes ahead then I'm going to be have to work later into the evenings sometimes, just negating the increase in outsid

Unix & friends use a file or set of files with daylight-saving time changes; it's updated everytime somebody changes things. In Debian, it's in the tzdata package, described thus:

This package contains data required for the implementation of standard local time for many representative locations around the globe. It is updated periodically to reflect changes made by political bodies to time zone boundaries, UTC offsets, and daylight-saving rules.

Every time (*ahem*) some gov't tweaks the rules, the new info is encoded, and the updated package is sent out. Note that the superseded info is retained, so that if you ask about a time in 1974 in New York City, it'll adjust correctly for the idiotic Nixonian ``let's all go to work in the dark'' time.

Debian's files live under/usr/share/zoneinfo, and amount to a bit over 6MB of data.

Man, this again? We get this from the english MPs every other week. This is the same ol' same ol' with a slight variation of +2 in the summer and +$unknown in the winter.For the Nth time, this is not going to happen, the rest of the UK wont agree to it. Scotland is much further north than its mild weather would suggest, and when this was tried shortly after the second world war it was an unmitigated disaster. It was dark till lunchtime in the winter in the Shetland Isles, for little gain in the evening in the summer. And remember we almost have 24 hour daylight in Scotland in the summer, we dont need an extra hours daylight at 3am. And neither we, the Northern Irish, nor the Welsh care if it's dark in England 24 hours-a-day all year round;-)Every time the government changes and the Conservatives get in they start going on about this. The 'Tories' are an english party, and in England it gets dark at 10pm in the summer. Boo-hoo. It gets dark in Spain at 9pm in the summer, but they are out having beers till 3am. In England everyone is in their beds at 10pm, what do you want an extra hour of light for? Why do you want it to be light while you are asleep or in your house watching cricket and drinking warm beer or whatever it is you guys do? Especially if it's raining. I may be scottish but I've never seen so much rain as I have in Oxfordshire. No wonder you like your boats, you need them.It's not your timezone you want to change, it's your culture. You want to enjoy your evenings more? Get out more, talk to people in bars without waiting for a formal introduction. It doesnt have to be light outside to have a good time.

Fecking sassenachs. The next time you bring this up we're cutting your power and water.

Its not just you scots who don't want it, plenty of us english arn't too happy either!

I don't much care if its dark when I drive home from work , I'm already awake and have lots of coffee inside me. What I DONT want is it pitch black first thing in the morning when I'm half asleep trying to drive down dark roads with kids trying to get to school crossing said dark roads.

Why the fuck our politicians want this I have no idea. We're more north west than all of the rest of western europe bar ireland which means the time our sun rises and sets bares little resemblence to what happens in germany 500 miles east or france 200 miles south.

Also , can someone explain whats the point of a clock if it doesn't give at least a rough approximation of the real time?

However, given the British obsession with world war two, this may be an appropriate move - it will be like returning to 1940-1945, when they had "double summer time", mainly so people could work in their gardens, growing vegetables, after they got home from work. Somehow, i don't think this is what they'll be using the extra hour of evening daylight for this time round though - it will be simply an excuse to get more drunk in the evening (if that's possible).

The Australian government likes to mess with the day light offset for sporting events and I think they gave everyone a whole 5 weeks advanced notice a few years back. You get to the point where you just tell computer clocks to keep a common offset and then go change it twice a year.

There are some master time zone files that can be found here:ftp://elsie.nci.nih.gov/pub/ [nih.gov]On Unix like system you can run a command like # zic australasia (or whatever zone is messed up.. or just run them all).

I'm a UK taxpayer and I conduct a lot of business with the US west coast. Presently, we're 8 hours apart for most of the year, and that means that I can *just barely* squeeze in a conference call with Californian colleagues (I'm co-owner of boingboing.net and all my partners are in LA and San Francisco) and still get out of the office in time to get my daughter from day-care and get home for dinner.

If the timezone difference goes to 9 hours, I'm buggered. The additional hour will have a direct, negative impact on my net income, as it will either require me to participate less in these transatlantic ventures (for example, it would probably mean no more freelance assignments for US editors, all of which generate UK taxes) or hire expensive babysitters to fetch the kid from day-care (something I also would rather not do for sentimental reasons having nothing to do with the economy).

It's a conference call... why can't you just leave work at 16:00 or 16:30 to pick up your kids, and join the call from your house at 17:00 or 17:30 ? What difference is it if you join from your home or office?

Or you'll have to get a bit more imaginative at finding solutions like anyone currently working with the Far East and Australasia does. It's not that I don't care about the inconvience this would cause you, I just don't care about it anymore than the inconvience the current system causes others. I find it very difficult to care about whether it happens or not, both options have merit and will suit different people and geographical parts of the UK better/worse.

Various exchanges open at 07:00 around the world, local time. Which gives London a 1 hour edge on the rest of Europe for trading.Combine that with your observations on scheduling, and the fact that we speak English, and you've got the three reasons as to why London is treated as the "gateway to Europe" by many businesses.

Get rid of that, and you have to ask why you wouldn't just deal through somewhere like Madrid...

It may not be a problem for high end hardware, but lower end embedded controls with real-time clocks often use hard coded DST algorithms. For example the EU has defined standard DST dates for years in advance, these change-over dates are often hard coded into low-end devices, but with a default +1 advance. This allows a simple hardcoded table to be added to the hardware without the need for any user configuration, other than setting the initial time and date. Short sighted perhaps, but the reality is that t

I mean if our politicians really don't see why clocks should tell a good approximation of the actual time why just 2 hours? Why not move them forward 12 hours and then it can be dark while we work but we'll have a nice bright nighttime for all those whingers to go out and have their cappucinos at 11pm or whatever the hell it is they want to do in the light late at night.

Sorry , but I don't see the point of daylight saving AT ALL. Contrary to what some morons seem to believe we (surprise!) don't get an extra hour of daylight. The real problem isn't the time, its the fact that the working day is spread unevenly around midday. If everyone started work at 8am and finished at 4pm then this wouldn't be an issue. If you really need the extra light in the evenings get up earlier - thats all you're doing anyway when the clocks go forward!

"I have made a decision to cancel the move back to 'winter' time starting from autumn this year", Russian president Dmitry Medvedev said on Tuesday, February 8, 2011. The new legislation eliminates the yearly switch between standard time and daylight saving time.

I totally agree, and I love the fact that Russia just "did it". Maybe other European countries won't be so scared if they can follow the lead instead of taking charge themselves so that we can finally end the nonsense.

Oh and by the way I live in Norway, were DST has a pretty strong effect on the sunlight. Just about every autumn the DST is discussed in the media, because people are so sick and tired of messing up their day rhythm. We don't care a

The families of Indian call centre employees will be happier - it means that their sons and daughters will be one hour less from the rest of India. If the UK were to be so generous to go +5.30 onto Indian time, even better

I recently worked on a trading system that had 50 columns for the half-hours in a day, to accommodate the long day when the clocks go back. So if this happens, they have 6 months or so to expend it to 52 columns and to make sure all the clock changing logic still works with a two hour change. I thought they were considering year-round daylight savings - maybe we will go forward two hours then back only one, and then stabilize at those UTC offsets, so our clocks then match CET. I bet a lot of Europhobes will

This is the exact same BS reason that the US screwed around daylight savings time, with the misguided idea that it would somehow save energy.

These kinds of things might have mattered 50 years ago, but they simply do not in today's 24/7 economy. If people want to shop, they will go out and shop, they won't stay home because it is dark outside.... heck they would just shop online anyway.

The idea that somehow giving an extra our of daylight is going to have any noticeable impact on a national economy is ridicu

Currently, for five months of the year it's dark when I leave the house in the morning and it's dark when I get home at night.

There's no time more depressing than end October when the clocks go back. I've spent the previous few weeks going to work in the dark. Now I get to see the sun coming up on my way in (really useful NOT!) and I know I won't see the Sun in the evening until the clocks change again.

So very wrong. United Kingdom = state. England, Scotland, Wales, Northern Ireland = countries. Ulster (Northern Ireland + 3 counties in Eire) = province. Great Britain (or just Britain as we're not so big-headed these days) = England + Scotland + Wales + islands (but not Northern Ireland, and definitely not Eire). Nationality of a UK subject - as we're subjects of the Crown rather than citizens of the state - is British.